Folding carton



Patented Dec. 31, 1929 v UNITED STATES A PATENT OFFICE FOLDING CARTONApplication filed December 24, 1927. Serial No. 242,826.

, The present invention relates to foldable paper or cardboard boxes orcartons, and aims to provide an eflicient and improved corner structurefor boxes of this character.

Accordingly, I have devised. an improved construction adapted to beembodied in blanks of sheet material, whereby a novel, practical andeconomical corner structure is produced which permits quick operation inlo folding the parts into box-shape, and results in a neatand securelylocked relation of the parts of the blank at each corner of the box.

With these general objects in view the invention' will now be describedby reference to the accompanying drawing illustrating one form ofconstruction which I have devised for'embodying' the proposedimprovements, after which the novel features and combinations will bedefined in the appended claim.

In the drawing Figure 1 is a plan view showing a box or carton blankembodying the present features of improvement;

Figure 2 is a perspective view showing the blank folded into-box orcarton form; and

Figures 3 and 4 are detail perspective views, on an enlarged scale,illustratin successive steps in the operation of assem ling the cornerstructure.

Referring now to the drawing my invention is therein illustrate inconnection with a box blank or pattern adapted to be made up'from sheetmaterial such as paper, card-board or the like, and scored as 1ndicatedat 10 to permit folding to form the sides 11, and at 12 for forming theends 14, the portion 15 bounded by the scoring 10-12 defining either thebottom or cover portion of the box, the up r and lower parts of whichare of course uplicates excepting that the cover is made slightly largerthan the bottom in order to telescope over the latter.

At each corner of the blank the end 14 is formed with an extension orwin 14: projecting a distance equal to the wi th of the side 11 andadapted to be folded along the same line 10.' In the cutting of theblank, each wing is separated from the corresponding side 11 by a cut 16in line with the fold in detail, I

path of the outer corner of the win 14' duror score line 12, and at thesame time a diagonal slit 17 is produced in each wing from the corner orintersection of the lines 1012 and extending to approximately the centerof the wing as indicated at 17 This forms a locking tab 18 which isadapted to be folded, first along a score line 19 extending from thepoint 17 to the outer end of the cut 16, and then along a second scoreline 19' extending from said point 17' to the cut 16 and at right anglesthereto.

In the cutting of the blank each side, 11

1s formed with a slit 20 near each end, of slightly angular outline asillustrated to facilitate spreading of the edges of the slit 65. for theinsertion of the folded locking tab 18, the length of the slit beingjust sufiicient to allow insertion of the tab, after it has been folded,into locking position. The principal dimension of each slit 20 follows aline inter- 7 -secting the adjacent corner, and terminates at a distancefrom said corner equal to the length of the cut 17; this insures therigid locking of the corner structure by engagement of the point 17' orclosed end of the cut or slit 17 with the adjacent end of the slit 20,after which the locking tab is opened and pressed back flat against theinside of the box to complete the corner assembly, as illustrated inFigure 2. so The method of folding and assembling the corner structureis illustrated in Figures 3" and 4. The locking tab is first foldedalong the score line 19 as indicated by the dotted line position inFigure '3, and then the tab is folded a second time along the score line19 as represented by the fulllines in said view. After the correspondingsides and ends 11 and 14 are folded along the lines 10 and 12,respectively, the wing 14 is foldedto lap over the end portion of theadjacent side 11, and the folded tab 18 is inserted through the slit 20in the manner illustrated in Figure 4;, where the dotted arrow-linerepresents the ing this inserting movement, whic is completed onengagement of the point 17 which I acts as a retaining shoulder at thebase of the locking tab, with the lower end of the slit 20, I

after which the tab 18 is folded back in the opposite direction intoflat position against the inner face of the side and with one edge ofthe tab in snug frictional binding engagement with the inside bottomface of the box, as clearly illustrated in Figure 3. This produces astrong and rigid locking connection between the side and end portions ateach corner, as the snug engagement of the points 17 with the ends ofthe slits 20 allows no loose play, and the parts can become disengagedonly with difficulty. It will be noted that in the completed box, eachlocking tab 18 not only engages snugly against the bottom of the box onits interior, but extends entirely into the adjacent corner, so that ineach completed corner structure the locking tab forms in effect a strongsupporting truss for supporting and bracing the overlapping portions ofthe sides and ends at that corner of the box. It will also be noted thatthe angle of slit outline 20 is such as to allow free passage of thetabs when inserting the same and yet not so sharp an angle as to form anear or tab which would be likely to sag outward and catch on otherobjects.

A simple and inexpensive construction is thus produced, the blanks forwhich may be stamped economically from the sheet material with a minimumof waste, and, as above explained, the blanks may be folded convenientlyand quickly into box form, ready for use.

WVhile I have illustrated and described what I now regard as thepreferred form of embodiment of my invention, I desire to reserve theright to make all such changes or modifications as may fairly fallwithin the scope of the following claim.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

A box corner construction comprising a blank formed with folding sideand end portions one of which is formed with a slit and the other with awing extension providedwith a folding locking tab formed by a slitextending from the center of said wing extension to the box corner, saidtab portion being provided with a score line extending from the centerof said extension to the outer corner of the tab and a second score lineextending from said wing center at substantially right angles to theinner edge of the tab, thereby facilitating folding of the tab andinsertion of the same through said first slit in assembling the cornerstructure, the center point of said wing extension having retainingengagement with one end of said first slit as the tab is again opened onthe inside of the box.

In witness whereof I hereunto affix my ARCH 0. LONG.

signature.

